package Day07;

public class Demo01 {
    public static void main(String[] args) {
        Nurse n = new Nurse();
        practice(n);

        Student s = new Student();
        practice(s);
        s.show();
    }
    public static void practice(Person p){
        Student s = new Student();
        if(p instanceof Student){
            p = s;
            p.say();
        }else{
            System.out.println("请输入学生对象");
        }
    }
}
